The primary objective of the proposed program is the ultimate development of a practical Wearable Air Power Supply for an implanted pneumatic artificial heart. The proposal addresses itself to the concept of a Wearable Power Supply for a pneumatic heart that has been implanted in an ambulatory patient, and seeks to identify the smallest and lightest pneumatic drive for the application, so that a unit can be continuously worn on a belt or harness without undue discomfort. A preliminary analysis of a Wearable Pneumatic Supply has been made. Air is supplied by a motor-driven partial emission centrifugal blower. The air flow is controlled and directed by an electrically piloted pneumatic valve powered by the blowers output pressure. A preliminary layout of a package using readily available commercial components has been made. The unit has sufficient battery capacity for operation of one hour or more. The total package volume is 56 cu. in. and the weight is 3 lbs., of which half is due to the batteries. Five-hour operation or substantial reduction in size and weight is achieved by advanced lithium batteries. The Wearable Air Supply also can be adapted for application as a personal and portable respirator, which could free a patient with respiratory failure from being confined and tethered. The Phase I Proposal is for a feasibility study for an optimal design of a Wearable Air Supply for a pneumatic artificial heart. The study will identify state-of-the-art and developmental air pump designs, motors, bearings and batteries. A design configuration will be recommended for development.